Flat lamp



FIG. 1 is a front plan view of the present invention;

FIG. 2 is a side plan view of the present invention;

FIG. 3 is a top plan view of the present invention; and,

FIG. 4 is a back plan view of the present invention.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a flat lamp, as shown and described. 